Spyre Therapeutics (NASDAQ:SYRE) shares climbed 25% on Monday after the company reported that its investigational therapy SPY001 achieved its primary endpoint in a Phase 2 study targeting ulcerative colitis.
The biotech group released 12-week results from Part A of its SKYLINE trial, showing that SPY001 delivered a statistically significant 9.2-point reduction in the Robarts Histopathology Index. The treatment, an anti-α4β7 antibody, is being developed for patients with moderate-to-severe ulcerative colitis.
Secondary measures were also encouraging, with clinical remission observed in 40% of patients and endoscopic improvement seen in 51%. The Modified Mayo Score fell by 3.7 points from baseline.
A total of 43 patients were enrolled in the study. SPY001 demonstrated a safety profile consistent with other drugs in the α4β7 class. Six participants experienced treatment-emergent adverse events during the induction phase, including one serious event that was not considered related to the drug. Back pain was the most commonly reported side effect, affecting two patients.
Enrollment for Part A of the SKYLINE trial has now been completed, and the company has moved on to recruiting patients for Part B. This phase will include three monotherapy arms and three combination cohorts, testing SPY001 alongside additional investigational antibodies, SPY002 and SPY003.
Spyre said it expects proof-of-concept data from the remaining Part A cohorts in mid-2026 for SPY002 and in the third quarter of 2026 for SPY003. Readouts from Part B across all cohorts are currently anticipated in 2027.
The company is positioning SPY001 as a potential best-in-class anti-α4β7 therapy, designed with an extended half-life to improve durability and outcomes compared with existing treatments for inflammatory bowel disease.